Pfizer’s resurgent rare disease drug Vyndaqel has had its uses extended by the EMA, becoming the first drug in the EU for cardiomyopathy resulting from rare disease transthyretin-mediated amyloidosis (ATTR).
Vyndaqel (tafamidis meglumine) has been approved since 2011 for stage 1 polyneuropathy associated with ATTR, but the cardiomyopathy approval significantly extends the eligible patient population for the drug, already growing quickly following its approval for the latter indication in the US last May.
Sales of the once-daily, oral drug picked up dramatically after it was approved by the FDA, reaching $213m in the fourth quarter from $39m a year earlier, and the EU approval will help it achieve its long-anticipated blockbuster status.
In the ATTR polyneuropathy indication it has competition from Alnylam’s injectable drugs Onpattro (patisiran) and Ionis’ Tegsedi (inotersen), which were approved for that use in Europe in 2018.
Cardiomyopathy is the most serious of the symptoms seen in patients with hereditary or wild-type ATTR, a condition that means a type of amyloid protein known as transthyretin gets deposited in organs, stopping them from working correctly. In the heart, it causes stiffness in the muscle walls that impairs pumping and can lead to heart failure.
The latest approval is based on the results of the phase 3 ATTR-ACT study, showed that Vyndaqel reduced all-cause mortality over a 30-month period by 30% compared to placebo in patients with ATTR cardiomyopathy, reducing the death rate from around 43% to 29.5%.
Prior to Vyndaqel, treatment options for patients with ATTR cardiomyopathy were restricted to symptom management and – in rare cases – a heart transplant, according to Pfizer.
The lack of alternatives and mortality data has driven rapid take-up of the drug in the US, as well as diagnosis of the disease.
By end of 2019 more than 9,000 ATTR cardiomyopathy patients had been diagnosed in the US – raising the diagnosis rate from 1% pre-Vyndaqel launch to around 9%, according to Pfizer.
Meanwhile, more than 5,500 patients had been prescribed the $225,000 per year drug at that cut-off, and over 3,000 had already received it. The drug has also been approved for the cardiomyopathy indication in Japan, Brazil and Canada.